The moment in 1953 where Arthur Godfrey sacked popular young crooner Julius LaRosa on air was one of the first examples America saw of how the power of a network show can twist the mind of its host, causing him to lose all humanity, … . However, by the time Letterman retired in 2015, he had several moments on the same scale, if not arguably worse than Godfrey’s. Zinoman mentions some of Letterman’s creepiest, such as crude on-air flirting with supermodels, and a self-loathing alter-ego character called “Creepy Dave” who would appear on screen using videotape and split screen and silently stalk Letterman-Prime. As Zinoman writes, “Peter Lassally, who produced The Tonight Show, said he found Creepy Dave truly creepy. ‘It’s that stare— something very unpleasant. Dave tells him to get out, but Creepy Dave won’t go. …’”
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As one Letterman staffer quoted by Zinoman says, “There comes a moment when he turns on you.” It’s brutal, revelatory stuff, but curiously, Zinoman leaves out one of Letterman’s worst moments, this one on-air. It happened in 2006, and by then, I had largely stopped watching most long-form TV … But if Letterman was on in a hotel room while traveling, I had no qualms about leaving him on in the background.

And then Letterman had Bill O’Reilly on as a guest. While sparring, O’Reilly asked Letterman a simple question: “Do you want the United States to win in Iraq?”

… Townhall’s Douglas MacKinnon wrote of the moment where Dave truly dropped the Carsonesque Midwestern boy made good mask, “To the surprise of no one but his sycophants, Letterman could not or would not answer the question. When pressed by O’Reilly to answer, the best he could do was to play to his mostly left-leaning audience for cheap debating points and say, ‘It’s not easy for me because I’m thoughtful.’”

Or as I added at the time, “How thoughtful do you need to be? it’s an A or B question: Do you want the US to win, or Al Qaeda, the Baathists, and Iran? Letterman, who, 20 years ago, was once the master of postmodern irony, became its unintentional victim as he unwittingly echoed Jack Benny’s classic gag when he retorted to a fictional mugger shouting ‘Your money or life, pal!’ on his old radio show: ‘I’m thinking it over!’”

My wife and I used to watch Jay Leno fairly regularly (I can’t remember whether by recording or if we stayed up that late). But then at one point NBC got greedy and demanded that our satellite provider (and others, I assume) pay much more than the provider was willing to pay. The result was no NBC stations for a year. During that time we tried Letterman. He had some amusing bits, but he still left us cold. When NBC was back on satellite we were back on Leno. As this summary of this Letterman bio suggests, I don’t think Letterman likes much of anybody, not even himself.